1. Field
The present application relates to a phase adjusting apparatus and a camera.
2. Description of the Related Art
Recently, accompanying an increase in the number of pixels in an image pickup device, there is an increasing demand for an electronics device, such as an electronic camera, to increase the transfer rate of digital data. In the design of such an electronics device, a relationship of phase between data and clock is maintained by suppressing variations in delay of data by controlling the impedance of a transfer line, making wires the same length, selecting the material of printed board, etc., and by performing a simulation of signal waveforms, etc.
It is known that the relationship of phase between data and clock changes due to heat generated in a continuous operation of an electronics device or the configuration of a peripheral circuit. As an example of measures to prevent this, Japanese Unexamined Patent Application Publication No. 2008-124714 discloses a configuration of a circuit that adjusts a relationship of phase between data and clock using two kinds of clock with different phases as well as adjusting a threshold value to determine the voltage of an input signal.
However, with the technique disclosed in Japanese Unexamined Patent Publication. No. 2008-124714 described above, it is actually difficult to determine a threshold value for determination of voltage and there is yet a room for improvement in a point that it becomes hard to maintain the precision of the two kinds of clock if the clock speed is increased.